Cutting machine



1-1. zlgnsamom CUTTING MACHINE Filed May 9, 1932 Dec. 5, 1939.

rm 3 m1? m mw7 fl m 3M a MAP 7 ah Patented Dec. 5, 1939 PATENT OFF-lCUTTING MACHINE Harold Eugene Edgerton, Water-town, Mass. ApplicationMay 9, 1932, Serial No. 61%,045

19 Claims.

The present .inventlon relates to cutting machines, and moreparticularly paper-cutting machines and the like.

An object of the invention is to provide a stroboscopic control for.machines of the above-= described character.

A further object of the invention is to aid in speeding up the operationof cutting machines.

Another object is stroboscopically to enable the operator to correct forerrors in register.

Other. and further objects. will be explained hereinafter and will beparticularly pointed out in the appended claims. I

The invention will now be described in connection with the accompanyingdrawing, the single figure of which is a diagrammatic view of circuitsand apparatus illustrating the invention in its preferred form. I

' A mercury-arc tube 2 is shown provided with a mercury-pool cathode 4and an anode 6. The tube may be of the long, slender form illustrated,or it may have any other shape, such as zig-zag or helical. It may beprovided with a restricted neck (not-shown) at'its lower end to permittilting the tube to a horizontal position, though this o is notessential.

The cathode 4 and the anode 6 are shown respectively connected byconductors 0 and I0 to a main discharge condenser 26. The tube 2 and themain discharge condenser 26 are connected directly to each other,through a cur rent-limiting impedance 35, which usually is a combinationof resistance and inductance. The size of the capacity 26 is increaseduntil there is sufficient light for the frequency of flashing. Slowspeeds need a larger capacity than fast speeds.' Energy to the condenser26 comes from the source of direct current, after passing-through thecurrent-limiting impedance 35. The directcurrent supply for thecondenser 26 may be one or more batteries (not shown), direct-currentgenerators, thermionic or gaseous-discharge rectifiers 20, 22, forproducing a conventional, fullwave, rectifier circuit, or any othersources of direct current. The rectifiers 20, 22 may be connected with asource I44 of alternating current in any well known manner, as by meansof the secondary winding I41 of a transformer I43. A capacitance 25 ispart of the source of direct current and its function is to maintain asupply of energy between the pulses of power given by the rectifierunits 20 and 22. The invention may, however, be used in connection withalternatingcurrent sources (not shown).

The conductor I0 terminates upon the anode 6, one terminal of thecondenser 26, and one end of the direct-current supply for the condenser26. The conductor 8 terminates upon the cathode 4, the other terminal ofthe condenser 26 and one end of the series impedance 35. The oppositeend of the impedance 35 is connected directly to the other end of thedirect-current supply for the condenser 26. The series impedance mayequally well be disposed in the positive side of the battery, in serieswith the conductor I0. I

A small condenser 28, opposite terminals of whichare shown at 43 and 44,is connected in series with an impedance 3| across any desirable sourceof direct current, which may be the direct current supply for thecondenser 26.

A conductor 39 leads from the terminal 43 of the condenser 28 to oneside of the primary 36 of a step-up transformer 30. From the other sideof the primary 36, a conductor 4| completes the circuit through athermionic tube I40, such as a Thyratron tube, and an adjustableimpedance I9, to the other terminal 44 of the condenser 20. It isunderstood that the transformer and the impedance l9 may be in eitherthe anodeor cathode circuit. The use of the Thryatron tube makes itpossible to operate the circuit without any moving parts, except forcausing the Thyratron I40 to function. The Thyratron I40 is shownprovided with a cathode 48, a grid 50 and an anode 52. The terminal 43of the condenser 28 is connected by a conductor 45 with a point 38 ofthe conductor I0, the circuit continuing by way of the conductor 39, theprimary winding 36 and the conductor 4|, to the anode 52. A conductor 42connects the cathode 48, through the impedance I9, with the otherterminal 44 of the condenser 28. The condenser 28, the Thyratron tubeI40,

and the primary winding 36 are thus all connected in series. Thequantity of stroboscopic light is determined by the, amount of energy inthe condenser 26.

The secondary 29 of the step-up transformer 30 is connected to thecathode 4 and to an external condenser electrode or grid I00 on theoutside of the mercury-vapor tube 2, around the mercury pool. Theexternal condenser electrode I00 may be of any form, such as a wire-meshscreen, a I

wire wound around the tube 2, or a metal foil attached to the surface ofthe glass. For clearness, however, the electrode I00 is shown in thedrawing as slightly separated from the tube 2. The position of theexternal condenser electrode I00 is so chosen that the operation of thetube 2 is the most satisfactory. Under usual conditions,

the external condenser electrode I00 is the most effective when attachedtothe outside of tube 2, opposite the meniscus of the mercury. Itlikewise is posslble to employ an internal electrode ex-v cited from thesecondary 29 of the transformer 30 similarly to'the excitation of thecondenser electrode I00. This electrode may be placed either close tothe cathode or far from it in the tube. The operation of such aninternal starting electrade is not very satisfactory unless the tube ishot or unless there is a small amount of gas such as helium in the tube.

can;

' 75 Myer web 56 along lines 46 between printed It will also beunderstood that the sudden,

5 former 30. The transformer 36 establishes a suddenly applied highpotential gradient between the external electrode and the cathode. Theaction of this is to initiate the arc discharge through the tube.

The mercury-arc lamp is normally ineffective,

since the vapor is not ionized, and the mercuryspot source of electronsis not formed, but the lamp 2 has the charged condenser 26 connected toits anode 6 and cathode 4, with no limiting 5 resistance or reactanceexcept for that of the conductors l0 and 8.

The energy in the condenser 28 is discharged through the primary 36 ofthe step-up transformer 30, thereby magnetically inducing a very high.potential very quickly upon the external condenser electrode I06. Theeffect of this quickly applied, high voltage is such that the gas in thetube 2 is ionized and 'a source of electrons is caused to exist upon themercury cath- 26 ode 4. The main discharge condenser 26 discharges itsenergy violently into the tube 2 and part of this energy is transformedinto useful light. The flash of light is very intense and lasts aboutone one-hundred-thousandth of a second. Suflicient quantity of light isobtainable in this manner to take a photograph in this very short time.

The impedance I9 is adjusted until sufficient voltage is obtained tomake the operation satisfactory.

The are through the tube 2 is not maintained, because of the action ofthe impedance 35, which limits the current flow to such an extent thatthe arc is extinguished. The condenser v 26 is again charged before thenext discharge.

The inductance of the conductors 8 and I0 is useful in extinguishing theare, as it tendsto make the discharge current oscillatory. It is wellknown that the current of a mercury-arc tube does not reverse in thenormal operation, since there is no source of electrons on the anode;and thus, if the current becomes zero, due to the oscillation, it willnot be. established in the opposite direction.

The instantaneous current through the mercury-arc light-pulse tube isvery great, about one thousand amperes.

Although the operation of the tube 2 is satisfactory, when the vacuum isas close to perfect 65 as it is possible to get it by present-dayevacua-.

tion methods, the operation is likewise satisfactory when a small amountof gas, such as neon, helium, argon, air, etc., is put in the tube 2.These other gases cause modifications in the color of the light, becausethe characteristic'spectral colors of the gas are radiated when the tubeflashes. Other substances, such as sodium, aluminum, barium, iron, etc.,or various combinations of these, might also be employed as the cathodeat the bottom of the tube.

To aid in registering the cutter of a papercutting machine with theprinting on the paper by means of a stroboscopic light source of theabove described character arranged thereover,

a stationary switch member or members 32 is adapted to cooperate with amovable switch member or'members 34, shown operated by a rotatingknife-or knives 46. The knife or'knives 46 are adapted to cutperiodically a traveling portions 60 as the paperis fed by feed rolls 54from a printing machine, (not shown) or a roll of web. The speed of thepaper web 56 is manually controlled so that each knife 46, as' itdescends, shall always cooperate with a corre- 6 sponding knife 41 so asto out along the line 58. This, as practiced at the present day, is mosttiring on the eyes. The speed of operation is necessarily very low.According to the present invention, however, the knife orlcnives 46 are10 caused to energize the circuit of the mercury tube 2 by means of theswitch members 32 and 34. The paper will thus be stroboscopicallyilluminated by the tube 2 in synchronism with the knife or knives46"cutting the web 56. The 15 paper appears stationary to the eye whenit is illuminated by the stroboscopic light actuated from the knives,since the printing moves exactly one page for each knife. A stationaryreference marker 51 is purposely placed so that it 2 points to adistinguishing feature of the printing at the exact time of the flashfrom the tube 2 so that the web will be properly out when it comes underthe knife. It istherefore necessary merely to adjust the speed of theweb 56 manu- 26 ally, so that it always appears to be in the correctposition with regard to the pointer 51. If

'the web appears to move towards the knives,

the speed of the feed rolls 54 is decreased; and, likewise; if the webappears to drop back, the 30 speed of the feed rolls is increased. Thewaste is materially reduced and the speed of operation may be enormouslyincreased by the use of the invention.

I have shown the contacts 34 in line with the 36 knives 46 and, with thecontacts so placed, the light flashes occur at each moment the materialis-cut. It is apparent that the operation will be equally satisfactoryif the contacts 34 are displaced by a predetermined angle from the re 40spective knives 46, in which case the light flashes -'will have apredetermined phase relation with the cutting stroke of knives 46.

The stroboscopic lamp 2 is arranged so that its light falls upon theprinted web 66. In ac- 45 tual use, the lamp is usually put in ahorizontal position, directly above the reference marker 51. The maindischarge condenser 26 is directly connected to the mercury-arc lamp 2through the conductors 3 and I0. 5

The contact members 32 and 34 cause a momentary surge through a smalltrip condenser 59, which raises the potential of the grid 50 of theThyratron I46 to a high positive value with respect to the cathode 46when the contacts close. 65 After the surge, the condenser 59 ischarged, arid the grid 50 again becomes negative with respect to thecathode 49. At the instant the grid potential reaches a critical value,the anode 52 1 begins to complete the circuit 52, 48, I9, 42, 44, 60 28,43, 45, 36, I0, 39, 36, 4|, 52, containing the condenser 26 and theprimary 36; The energy stored in the condenser 28 is violentlydischarged into the low-impedance primary-36 through the Thyratron MB. Arelatively high voltage appears 65 across the terminals of the secondary29-01 the step-up transformer 30 and the main arc in the tube 2 isthereby started.

Ihecondenser 28 is again charged from the source of direct current. Thecharging current, 70 which flows from the temiinal 44, through theresistance 3|, causes a .voltage drop across the resistance 3|, which isnegative with respect to the cathode. This voltage dropis nearly equalto the voltage of the direct-current supply at the first instant, butbecomes smaller as the condenser 28 is charged. The grid 50 is connectedto the negative end of this resistance 3| through a resistance I42.Immediately after the condenser 28 discharges, the grid 50 is thuscaused to be very negative with respect to the cathode 48 and,

in this manner, the Thyratron I is prevented Thyratron I40 to oscillate.It is also possible to replace the resistance 3| by a reactance and theThyratron circuit will then generate its own oscillations at a frequencydetermined by the circuit constants and the characteristics of the tube.

Once the switches 32 and 34 become closed,

' they may remain closed without the Thyratron I40 flashing on againwhen the condensers 26 and 28 build up their voltages. The operation isindependent of the length of time that the switches 32 and 34 remainclosed, the complete function being performed at the moment when theyfirst become closed. It will also be understood that the surge in thegrid circuit of the Thyratron may be efie'cted in other ways, as by theuse of electrical transients in induc'tances, transformers or byimpulses from photoelectric cells, etc. The potential upon the grid 50of the Thyratron I40 controls the time of starting of the violentelectrical transients that cause the stroboscopic light.

A .resistance I43 is disposed across the condenser 59 in the gridcircuit, and has such a value that the condenser 59 discharges when theswitch members 32 and 34 are open between flashes in 'order to preparefor the next surge.

One characteristic of the present invention is that the light producedby the tube 2 may be of much higher instantaneous intensity than isattainable with mercury tubes the light of which is continuous, insteadof periodic. If the tube were subjected'continuously to the potential towhlch'the condenser 26' is initially charged, it would become destroyed.light thus periodically emitted by the high-current discharges of thetube at these high potentials, besides being of higher intensity, 'hasa. much larger proportion of components from the green, yellow and thered portions of the visible spectrum than is the case with the ordinarycurrent discharges produced with mercury tubes as at present operated.This light, in fact, is such as to compare very favorably with natural,white light. The invention is thus adapted to all the stroboscopic usesof, the present day, and also to many other uses where a light of goodwhite quality is necessary. The ultra-violet portion of the spectrumalso is found to have many additional components and those in theso-called near ultra-violet portion of the spectrum are very actinic andhence suitable for photographic work. In this respect thismercury-arc'stroboscope is far superior to others, such as those usingneon lamps.

It will be understood that the invention is not limited to use with thetype of tube illustrated. It is possible, for example, to employ a tubecontaining sodium, neon or other substances such as have been mentionedheretofore. The de- 75 scribed embodiment of the invention is, however,

It is, found'that the the best form that the invention has thus farassumed, from the points of view of emciency of operation, simplicity inconstruction and inexpensiveness.

It should be understood that the accompanying drawing, while itillustrates a preferred embodiment of the invention, is not theonly-circuit arrangement in which it is possible to embody theinvention. Modifications will occur to persons skilled in the art, andall such are considered to fall within the spirit and scope of theinvention, as defined in the appended claims.

What is claimed is:

1. A cutting machine having, in combination, means for feeding material,means for cutting the material, means for actuating the cutting meanstocause the cutting means to cut the material at predetermined points,stroboscopic means for illuminating the material comprising a tubehaving .two metal electrodes and anexternal'electrode, and meanssynchronized with the actuating means for establishing a high-potentialgradient between the electrodes and the external electrode.

2. A cutting machine having, in combination, means for feeding material,means for cutting the material, means for actuating the cutting means tocause the cutting means to cut the material at predetermined points,stroboscopic means for illuminating the material comprising a mercurytube provided with an external electrode, and means synchronized withthe actuating means for establishing a high-potential gradent betweenthe mercury and one of the electrodes.

3. A cutting machine having in combination, 1 means for feedingmaterial, means for cuttingthe material, means .for actuating thecutting means to cause the cutting means to cut the material atpredetermined points, stroboscopic means for illuminating the materialcomprising a tube, means for subjecting the medium in the tube to arelatively high potential, and means synchronized with the actuatingmeans for rendering the subjecting means periodically effective andinefiective. f

4. A cutting machine having, in combination, means for feeding material,means for cutting the material, means for actuating the cutting means tocause the cutting means to cut the material at predetermined points,stroboscopic means for illuminating the material comprising a tube, acondenser, and means synchronized with the actuating means forperiodically charging the condenser and discharging it through thetube'to cause pulses of light to be periodically emitted from the tube.

5. A cutting machine. having, in combination, means for feedingmaterial, means for cutting the material, means for actuating thecutting means to cause the cutting means to cut the material atpredetermined points, stroboscopic means for illuminating the materialcomprising a mercury tube, means for connecting the tube in an electriccircuit, and means synchronized with the actuating means for causingcurrent to flow in the tube periodically.

6. A cutting machine having, in combination,

means for feeding material, means for cutting the actuating means, andmeans controlled by a predetermined portion of the memberfor causingcurrent to flow in the tube in synchronism with the movements of themember.

7. A cutting machine having, in combination, means for feeding material,means for cutting the material, means for actuating the cutting means tocause the cutting means to cut the material at predetermined points,stroboscopic means for illuminating the material comprising a mercurytube, means for connecting the tube in an electric circuit, aperiodically movable member the periodic movements of which arecontrolled by the actuating means, and means for causing short intensepulses of current to flow in the tube in synchronism with the periodicmovements of the member.

8. A cutting machine having, in combination, means for feeding material,means for cutting the material, means for actuating the cutting means tocause the cutting means to cut the material at predetermined points,stroboscopic means for illuminating the material comprising a mercurytube, means for connecting the tube in an electric circuit, and aThyratron synchronized with the actuating means for periodicallysubjecting the mercury in the tube to a relatively high potential.

9. A cutting machine having, in combination, means for feeding material,means for cutting the material, means for actuating the cutting means tocause the cutting means to cut the material at predetermined points,stroboscopic means for illuminating the material comprising a mercurytube, means for connecting the tube in an electric circuit, atransformer for subjecting the mercury in the tube to a relatively highpotential, and means synchronized with the actuating means forperiodically opening and closing the circuit of the transformer.

10. A cutting machine having, in combination, means for feedingmacterial, means for cutting the material, means for actuating thecutting means to cause the cutting means to out the material atpredetermined points, stroboscopic means for illuminating the material,comprising a mercury tube, means for connecting the tube in an electriccircuit, a transformer for subjecting the mercury in the tube to arelatively high potential, a periodically movable member the periodicmovements of which are controlled by the actuating means, and meanscontrolled by the member for opening and closmg the circuit of thetransformer substantially in synchronism with the periodic movements ofthe member.

11. A cutting machine having, in combination, means for feedingmaterial, means for cutting the material, means for actuating thecutting means to cause the cutting means to cut the material atpredetermined points, stroboscopic means for illuminating the materialcomprising a source of electric energy, a condenser connected with thesource so as to be charged from-the source, a transformer having aprimary winding and a secondary winding, means for charging the primarywinding from the condenser, a mercury tube, and means synchronized withthe actuat ing means for subjecting the-mercury of the tube to thepotential of the secondary winding.

12. A cutting machine having, in combination,

means for feeding material, means for cutting the material, means foractuating the cutting meansto cause the cutting means to cut thematerial at predetermined points, stroboscopic means for illuminatingthe material comprising a source of electric energy, a condenserconnected with the source so as to be charged from the source, atransformer having a primary winding and asecondary winding, a vacuumtube having an input circuit in which the condenser is connected and anoutput circuit in. which the primary winding is connected, a mercurytube,

and means synchronized with the actuating means for subjecting themercury of the tube to the potential of the secondary winding.

13. A cutting machine comprising means for feeding material, means forcutting said material at predetermined points, said means including aluminescent discharge device for illuminating said material, meanssynchronized with said cutting means for causing a surge of current toflow through said discharge device, and means for'adjusting the relativeposition of said material and said cutting means.

14. A cutting machine comprising means for continuously feedingmaterial, means for cutting said material at predetermined points, saidmeans including a luminescent discharge device for illuminating saidmaterial, a condenser, and means synchronized with said cutting meansfor periodically charging the condenser and discharging it through thedischarge device to cause surges means. 16. A cutting machine comprisingmeans for continuously feeding material, means for cutting said materialat predetermined points, said means including a luminescent dischargedevice for illuminating said material, a condenser, means for chargingsaid condenser, and means having a predetermined phase relation withsaid cutting means for periodically causing said condenser to dischargethrough said discharge device.

17. A switching system of the character de' scribed comprising a lamphaving an anode, a cathode and a grid; a current supply circuitinterrupted by the said cathode and anode, a capacity across the anodeand cathode, and a breaker circuit interrupted by the grid and cathodeand including a source of current.

18. A switching system of the character described comprising a lamphaving an anode, a cathode and a grid, a current-supply circuitinterrupted by the cathode and the anode, a capacity across the cathodeand the anode, an electric system having a circuit interrupted by thegrid and the cathode, the electric system including means for biasingthe grid, and means for controlling the flow of current in the electricopening and closing the circuit.

HAROLD EUGENE EDGERTON.

